Drug delivery systems which use iontophoresis techniques have been proposed over the years. One such system is described, for example, in my pending application, Ser. No. 051,079, filed on May 15, 1987 and entitled "Drug Delivery Systems". The system discussed therein uses a housing unit which includes a microprocessing system for controlling a separately housed programmable power supply which supplies d-c electrical current pulses to an electrode structure containing a medication, or drug, to be delivered to a selected body location of a patient, e.g., transdermally. The electrode is connected to the power supply unit via a cable and the microprocessing system can respond to information concerning a large variety of drugs so as to calculate the drug del-very rate for any particular predetermined identifiable drug and to control the rate of delivery of such drug automatically. The microprocessing system is generalized in its operation so as to control the delivery of a large variety of medications and the housing is designed to include a display means, alarm circuitry, and a card reading system for permitting the identification of a particular drug when the system is to be put into operation. While somewhat portable in nature, the system is normally intended essentially for use in a hospital environment, or in a doctor's office, for example, and cannot be readily carried about or used by a patient outside such environment during the patient's normal activities.
It is desirable, however, in some cases, to make available to a patient a complete drug delivery system which is capable of being carried by, or suitably attached to, the patient and used by the patient even when performing normal activities. It is further desirable that such a system be arranged to deliver a particular drug in a controlled manner automatically once it has been so attached, without in many cases the patient needing to be constantly aware at all of its operation.